This invention relates to an electrical appliance, in particular an appliance for hair removal and/or hair care, with at least one electric power unit, an electric circuit connected thereto and including an On/Off switch, and a fluid circuit feeding a fluid from a reservoir to an application site which is open to atmosphere and where fluid is withdrawn from the fluid circuit.
An electrical appliance of this type in the form of an electric shaving apparatus is known from DE 199 07 025 A1. The known appliance has an electric motor arranged in a housing and driving both the shaving unit of the shaving apparatus and a pump device. This pump device supplies a shaving and/or care fluid to an applicator element adapted to apply the fluid to the skin to be shaved or the hair. When the shaving unit is turned off, the pump device is also stopped, so that no more fluid is conveyed from the reservoir, and yet it is possible for fluid to leak out of the supply pipe connecting the fluid reservoir directly with the applicator, at least when the shaving apparatus is maintained in an inverted position for a prolonged time. It is also possible for fluid to escape undesirably through the throttle leading from the fluid reservoir to atmosphere.
It is therefore an object of the present invention to provide an electrical appliance of the prior art type which absolutely reliably prevents any inadvertent escape of fluid from the fluid circuit in particularly straightforward manner, with particularly low constructional effort, and with a minimum number of components.
According to the present invention this object is accomplished by providing for the On/Off switch, in overcoming an actuator travel, to be switchable between two end positions, in particular between two stable end positions, and to be coupled to an actuator of a shutoff valve of the fluid circuit.
The present invention may find application in a wide variety of electrical appliances which have a fluid circuit in addition to the electric circuit. These include, among other appliances, electric shavers affording the possibility of fluid application, epilators having such a fluid application possibility, steam irons, coffee or espresso makers or fluid-applying hair dryers or curling irons.
As On/Off switch a bistable pressure switch is preferably used, which has a cam control for controlling the actuator travel. These pressure switches with cam controls of the type known, for example, from ball-point refills for generating their advancing movement afford the advantage of creating an appreciable actuator travel in spite of compact construction, which can then be used effectively for actuation of the shutoff valve.
According to an embodiment of the invention which is of particularly straightforward construction and insusceptible to failure, the shutoff valve is realized as a clamping element capable of clamping together or releasing a hose section of the fluid circuit in dependence upon the position of the switch.
In another preferred embodiment of the invention, the shutoff valve is constructed as a seat valve or as a slide valve, in particular as a 2/2 directional control valve. The advantage of this embodiment is that it exhibits a particularly accurate control and switching characteristic and that the opening and closing behavior of such valves has no hysteresis and/or aging effects.
The On/Off switch may be manufactured particularly easily and with a very low number of components when it is acted upon by an interrupter spring which itself is part of an electric switching contact of the switch. Advantageously, the switching contact itself is then fabricated from an elastic material as, for example, spring bronze.
Advantageously, the On/Off switch is coupled to an actuating rod one end of which forms the shutoff element of the shutoff valve. In order to ensure particularly reliable operation it is an advantage for the actuating rod to be loaded by a spring element. When the spring element acts upon the shutoff valve in the closing direction, this reliably prevents fluid from escaping even in cases when components of the switching chain are defective. This additional spring element relieves the interrupter spring and enables the use of a two-part actuating rod whose manufacturing tolerances can be absorbed by the additional spring.
Further objects, features, advantages and application possibilities of the present invention will become apparent from the subsequent description of the embodiments. It will be understood that any single feature or any combination of single features described or represented by illustration form the subject-matter of the present invention, irrespective of their summary in the claims or their back-references.
In the drawing,
In a manner known in the art, the shaving head 3 is comprised of a centrally located intermediate cutter 6 for shaving longer hairs, which is disposed between two arched shaving foils 7 which cooperate with undercutters, not shown in the drawing, for shaving short hairs. The shaving foils 7 and the intermediate cutter 6 are mounted in a removable frame 8. The fluid dispensing device 4 is secured to this removable frame 8 to ensure that the application of fluid invariably takes place in direct proximity to the area to be shaved. In addition to receiving the fluid reservoir 5, the housing 1 also accommodates an electric motor 10 which serves to drive the undercutters of the shaving head in an oscillatory manner as well as to drive a pump 11, it being possible for the pump to be driven either directly or indirectly. According to the invention it is furthermore possible for the pump 11 to be driven by an electric motor assigned to it separately. The pump 11 is part of a fluid system communicating with the fluid dispensing device 4, as shown in
The pump 11 serves to operate the fluid circuit, conveying fluid from the fluid reservoir 5 to the fluid dispensing device 4. For this purpose, the pump 11 has an inlet 12 and an outlet 13 with an integrated throttle. This throttle limits the operating pressure in the fluid system. Through a first fluid conduit 14 the inlet 11 is connected to the applicator pocket 15 of the fluid dispensing device 4, which pocket is constructed as an elongate recess in an applicator housing 16. This first fluid conduit 14 is connected to the applicator pocket 15 in the pocket's left-hand end section when viewing the drawing.
Advantageously, the pump 11 is arranged in the interior of the fluid reservoir 5 which is constructed as a replaceable cartridge and is exchanged for a new one when the fluid is spent.
Depending on the amount of fluid consumed, the fluid reservoir 5 is filled with fluid 18 up to a specified level 17, and the region below the maximum fluid level may be filled with a storage material for improved binding of the fluid. Open-cell sinter materials are particularly suitable for this purpose. Terminating in close proximity to and above the bottom 19 of the fluid reservoir 5 is a riser 20 which presents part of a second fluid conduit 21. The fluid conduit 21 leads to the applicator pocket 15 to which it is connected in the pocket's right-hand end section when viewing the drawing.
Arranged in a firm press-fit in the applicator pocket 15 is the applicator element 22, such that its upper region on which an applicator surface 23 is provided protrudes over and beyond the applicator housing 16. The press fit between the applicator element 22 and the applicator housing 16 is only interrupted by at least one secondary-air duct 24 having an accurately defined flow cross-section. The applicator element 22 may be fabricated from a wick-type material or from a metal or plastics sinter material. Owing to its open-cell structure it possesses a capillary effect for liquids leading to complete wetting. For operation of the fluid system is it important for the cross-section of the secondary-air duct 24 to be matched exactly to the throttle in the pump outlet 13.
In
Connected to the pushbutton 29 is an actuating rod 30 whose end remote from the pushbutton 29 is constructed as a clamp wedge 31. Between this clamp wedge 31 and its abutment 32 the second fluid conduit 21 is passed which is of a hose-type configuration at least in the region of the clamp wedge 31. This hose-type configuration is obtained using an elastic hose material compressible with low forces. The actuating rod 30 is loaded by a spring 33 taking support on the housing to which it is joined firmly.
In the Off position shown in
This arrangement ensures that fluid is not allowed to escape from the fluid reservoir 5 even when the electric shaver is in an inverted position. Because the throttle of the fluid system is disposed in the pump outlet 13, that is, within the fluid circuit, thereby obviating the need to provide a pressure-relief valve towards atmosphere, the fluid circuit is completely sealed against atmosphere when the appliance is deactivated. In this condition the turned-off pump 11 prevents any fluid from escaping through the first fluid conduit 14.
When the motor 10 of the electric shaver is turned on by the On/Off switch 25, it drives both the undercutters of the shaving head 3 and the pump 11. Through the first fluid conduit 14 the pump 14 initially draws air from the applicator pocket 15. Like the applicator element 22, the applicator pocket 15 contains no fluid initially, which enables aspirated air to be further supplied through both the pores of the applicator element and the secondary-air duct. This air is forced into the fluid reservoir 5 through the outlet 13 of the pump 11 and the throttle arranged in the outlet, whereby the pressure rise thereby induced causes fluid 18 to be transferred via the riser 20 or the second fluid conduit 21 to the applicator pocket 15.
Once the fluid has reached the applicator pocket 15, a fluid stream develops in the lower region of this pocket, that is, between the mouths of the first and second fluid conduits. By virtue of its capillary effect, the arriving fluid is distributed in the entire applicator element 22 and transferred to the applicator surface 23. Any excess of fluid the applicator element 22 is unable to take up is extracted by the pump 11 through the first fluid conduit 14 and returned to the fluid container 5.
As long as the applicator element is still relatively dry and its pores mainly open, a very large volume of air is drawn by the pump 11, which results in a very rapid pressure increase in the fluid reservoir 5. This again leads to a very rapid transfer of the fluid 18 to the applicator pocket 15. With the fluid volume fed to the applicator element 22 increasing, its pores are gradually filled with fluid, and the secondary-air duct 24 is gradually closed by fluid. From this moment on an operating state prevails in which initially no additional air can be aspirated into the fluid system. The applicator pocket 15 is prevented from overflowing, only a fluid circuit is maintained in circulation. Not until a certain amount of fluid has been dispensed through the applicator surface 23 is air again allowed to be supplied to the system through correspondingly evacuated pores or a released secondary-air duct 24. This aspirated air volume then replaces the dispensed amount of fluid. The circulation system thus ensures that during operation the applicator element 22 is at all times sufficiently wetted, receiving an adequate supply of fluid 18.
As already explained with reference to
When the pushbutton 29 is depressed for a first time, the second camming element 37 rotates relative to the first camming element 35 through a predetermined angle, causing the respective tips of the two gears to lie end to end. As a result, an additional distance defining the actuator travel is set between the pushbutton 29 and the end piece 38. Due to the displacement of the end piece 38 in the guideway 36 against the force of the interrupter spring 28, electrical contact between the contact lug 26 and the contact element 27 is closed and, in addition, the actuating rod 30 is displaced to the right. The rod then displaces the intermediate member 40 and the clamp wedge 31 likewise to the right against the force of the spring 33, thus canceling the clamping action on the second fluid conduit 21. When the pushbutton is pressed a second time, the off-state shown in
In an alternative embodiment of the invention the switching valve 45 shown in
Provided on the outer contour of the valve closure element 49 in the area of the end 48 is a circumferential groove 54 which is engaged by a coupling yoke 55 constructed as part of an actuating head 56. The actuating head 56 in turn is connected to the actuating rod 30—see
A leg spring 57 is held on a bar-type projection 58 of the valve housing 50, with the coil-type center portion of said leg spring 57 embracing the projection 58. In this arrangement the first leg 59 of the leg spring 57 elastically biases the actuating head 56 in a direction effecting closing of the valve closure element 49 coupled thereto. To this effect, the end of the second leg 60 takes support upon a stop 61 of the valve housing 50. In the representation of
In contrast to the hose clamping according to
The section of the valve closure element 49 extending out of the valve housing 50 up to the groove 54 is encapsulated by an elastomeric bellows 62. This bellows 62 also serves as a valve spring acting in opening direction—though with a low spring force. As a result, the switching valve 54 operates in particularly clearance-free manner, enabling extremely short actuator travels to be realized.
Number | Date | Country | Kind |
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102 17 987.5 | Apr 2002 | DE | national |
Number | Date | Country | |
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Parent | PCT/EP02/14276 | Dec 2002 | US |
Child | 10969271 | Oct 2004 | US |